/ Thesaurus / T Synonyms of tertiary period Find synonyms for: Noun1. Tertiary, Tertiary periodusage: from 63 million to 2 million years agoWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: acerbity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language